<template>
  <div id="me">
    <!--查询表单-->
    <el-form :inline="true" class="demo-form-inline">
      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
          v-model="searchObj.subjectParentId"
          placeholder="请选择"
          @change="subjectLevelOneChanged"
        >
          <el-option
            v-for="subject in subjectNestedList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="searchObj.subjectId" placeholder="请选择">
          <el-option
            v-for="subject in subSubjectList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>
      </el-form-item>

      <!-- 标题 -->
      <el-form-item>
        <el-input v-model="searchObj.title" placeholder="课程标题" />
      </el-form-item>
      <!-- 讲师 -->
      <el-form-item>
        <el-select v-model="searchObj.teacherId" placeholder="请选择讲师">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"
          />
        </el-select>
      </el-form-item>

      <el-button type="primary" icon="el-icon-search" @click="fetchData()">查询</el-button>
      <el-button type="default" @click="resetData()">清空</el-button>
    </el-form>
    <el-table
      v-loading="listLoading"
      :data="list"
      element-loading-text="数据加载中"
      border
      fit
      highlight-current-row
      row-class-name="myClassList"
    >
      <el-table-column label="序号" width="70" align="center">
        <template slot-scope="scope">{{ (page - 1) * limit + scope.$index + 1 }}</template>
      </el-table-column>

      <el-table-column label="课程信息" width="470" align="center">
        <template slot-scope="scope">
          <div class="info">
            <div class="pic">
              <img :src="scope.row.cover" alt="scope.row.title" width="150px" />
            </div>
            <div class="title">
              <a href>{{ scope.row.title }}</a>
              <p>{{ scope.row.lessonNum }}课时</p>
            </div>
          </div>
        </template>
      </el-table-column>

      <el-table-column label="创建时间" align="center">
        <template slot-scope="scope">{{ scope.row.gmtCreate.substr(0, 10) }}</template>
      </el-table-column>
      <el-table-column label="发布时间" align="center">
        <template slot-scope="scope">{{ scope.row.gmtModified.substr(0, 10) }}</template>
      </el-table-column>
      <el-table-column label="价格" width="100" align="center">
        <template slot-scope="scope">
          {{ Number(scope.row.price) === 0 ? '免费' :
          '¥' + scope.row.price.toFixed(2) }}
        </template>
      </el-table-column>
      <!-- <el-table-column prop="buyCount" label="付费学员" width="100" align="center">
        <template slot-scope="scope">{{ scope.row.buyCount }}人</template>
      </el-table-column> -->

      <el-table-column label="操作" width="150" align="center">
        <template slot-scope="scope">
          <router-link :to="'/course/info/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
          </router-link>
          <router-link :to="'/course/chapter/'+scope.row.id">
            <!-- <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button> -->
          </router-link>
          <el-button
            type="text"
            size="mini"
            icon="el-icon-delete"
            @click="removeDataById(scope.row.id)"
          >删除</el-button>
        </template>
      </el-table-column>
    </el-table>

    <!-- 分页 -->
    <el-pagination
      :current-page="page"
      :page-size="limit"
      :total="total"
      style="padding: 30px 0; text-align: center;"
      layout="total, prev, pager, next, jumper"
      @current-change="fetchData"
    />
  </div>
</template>
<script>
import course from "@/api/course";
import teacher from "@/api/teacher";
import subject from "@/api/subject";
export default {
  data() {
    return {
      listLoading: true, // 是否显示loading信息
      list: null, // 数据列表
      total: 0, // 总记录数
      page: 1, // 页码
      limit: 10, // 每页记录数
      searchObj: {
        subjectParentId: "",
        subjectId: "",
        title: "",
        teacherId: ""
      }, // 查询条件
      teacherList: [], // 讲师列表
      subjectNestedList: [], // 一级分类列表
      subSubjectList: [] // 二级分类列表,
    };
  },
  created() {
    this.fetchData();
    this.initTeacherList();
    this.initSubjectList();
  },
  methods: {
    removeDataById(id) {
      // 
      this.$confirm(
        "此操作将永久删除该课程，以及该课程下的章节和视频，是否继续?",
        "提示",
        {
          confirmButtonText: "确定",
          cancelButtonText: "取消",
          type: "warning"
        }
      )
        .then(() => {
          return course.removeById(id);
        })
        .then(() => {
          this.fetchData();
          this.$message({
            type: "success",
            message: "删除成功!"
          });
        })
        .catch(response => {
          // 失败
          if (response === "cancel") {
            this.$message({
              type: "info",
              message: "已取消删除"
            });
          }
        });
    },
    resetData() {
      this.searchObj = {};
      this.subSubjectList = []; // 二级分类列表
      this.fetchData();
    },
    fetchData(page = 1) {
      // 调用api层获取数据库中的数据
      
      console.log("加载列表");
      // 当点击分页组件的切换按钮的时候，会传输一个当前页码的参数page
      // 解决分页无效问题
      this.page = page;
      this.listLoading = true;
      course
        .getPageList(this.page, this.limit, this.searchObj)
        .then(response => {
          //  设置断点调试
          if (response.success === true) {
            this.list = response.data.rows;
            this.total = response.data.total;
          }
          this.listLoading = false;
        });
    },
    //初始化教师
    initTeacherList() {
      teacher.getList().then(response => {
        this.teacherList = response.data.items;
      });
    },
    initSubjectList() {
      subject.getNestedTreeList().then(response => {
        this.subjectNestedList = response.data.subjectList;
      });
    },
    subjectLevelOneChanged(value) {
      for (var i = 0; i < this.subjectNestedList.length; i++) {
        var data = this.subjectNestedList[i];
        if (data.id === value) {
          this.subSubjectList = data.children;
          this.searchObj.subjectId = "";
        }
      }
    }
  }
};
</script>
<style>
#me {
  margin-left: 20px;
  margin-top: 20px;
}
</style>

<!-- 表格 -->